1. Field in the Industry
This invention concerns a process for obtaining a metal from a metal oxide as a reduced form. More specifically, the invention concerns a process in which a metal oxide is pulverized and the resulting particles are heated by high temperature flame and melted to carry out reducing reactions.
2. State of the Art
In conventional steel making using an electric furnace dust waste from the furnace is collected by a dust collector for the purpose of preventing air pollution.
The dust as a waste from steel making is very fine powder, and because of difficulty in utilization thereof, even though it contains FeO and Fe.sub.2 O.sub.3, the dust has been disposed as it is.
The steelmaking using an electric furnace also exhausts as wastes oxidation slag and reduction slag depending on the steps of refining.
Of the wastes, the oxidation slag is used as a roadbed material for constructing asphalt-paved roads. On the other hand, the reduction slag has no particular use, and thus, it is unavoidable to dispose.
The reduction slag contains, as one of the components, much free CaO, which absorbs water to be Ca(OH).sub.2. Volume expansion occurring at the time of this hydration makes it difficult to use the reduction slag as it is even for the roadbed material.
Disposing these dusts of course requires much cost, and the cost for disposing increases the costs for steel making.
The applicant proposed in a previous patent application (Japanese Patent Application No.6-11208) a method of mixing the steel making dust and the reduction slag by injecting them from nozzles of a burner into high temperature flame to melt.
This method gives the reduction slag physical and chemical properties similar to those of the oxidation slag, and thus, makes it possible to use the waste as the roadbed material.